3 Mar 2016

Results of a Turkish study have suggested further investigation is required into the validity of four new impulsivity symptoms proposed by the American Psychiatric Association.

The researchers aimed to evaluate the validity and added value of including the following impulsivity items in the Diagnostic and Statistical Manual of Mental Disorders – 5th edition (DSM-5™) criteria: impatience, acting without thinking, uncomfortable with doing things slowly and difficulty in resisting temptations, which are not currently included in DSM-5™ due to lack of evidence. The performance of these four symptoms was assessed in relation to ADHD factor structure; performance in predicting clinical impairment; ADHD diagnosis specificity; and the best symptomatic threshold in predicting clinical impairment.

A diagnosis of ADHD was ascertained using both a symptomatic assessment using rating scales and an interview with a psychiatrist to determine impairment (completed by 416 children aged 6–14 years and their parents). Children diagnosed with ADHD (according to both 18-item DSM-IV and the proposed 22-item DSM-5™ criteria, n=31; according to just one of the diagnostic criteria, n=20) were compared with children without ADHD (n=365).

Confirmatory factor analysis revealed that the addition of the four new symptoms would not change the factor structure when compared with models of 18 items, but that the additional items – particularly the item ‘difficulty to resist temptations’ – may be better at discriminating children with ADHD with severe ADHD latent traits. Although no single symptom was specifically associated with a diagnosis of ADHD, symptoms of impatience were a good predictor of impairment according to both parents and teachers. However, there was also no significant change in the accuracy for predicting impairment with the inclusion of the four new symptoms.

The researchers suggested that the value these additional symptoms add in terms of predicting impairment and factor structure is incremental and insufficient to warrant change to current diagnostic criteria. Bearing in mind the modest study size, they concluded that further investigation is required in order to best capture impulsivity symptoms in ADHD diagnostic criteria.